We've all seen way too many cases of mass murders in our public schools. There are even more examples of more pedestrian school shootings, and I mean cases of students shooting students or someone coming into the school to shoot someone during school hours. I'm not talking about some random bullet fired a half mile away, hitting a fence post in the middle of the night here.

Real school shootings do happen, and they happen more often than anyone should be comfortable with, even if most students never actually see any such thing happen in their schools.

To curb this, schools are declared gun-free zones. You and I, as law-abiding citizens, can't carry a firearm into the school when we've got something like a parent-teacher conference or something like that, because no one other than the police can be trusted with guns, you see.

And a situation that happened in New Orleans on Tuesday highlights just how little those rules do to protect anyone.

A lockdown at ReNEW Dolores T. Aaron Academy in New Orleans East has been lifted after a man entered the school with a firearm Tuesday morning.

Authorities say 24-year-old Mario Harris walked into the building with a gun, prompting an immediate lockdown of the campus.

Dozens of parents rushed to the campus, with some saying they heard the news on social media.

“The last thing a parent wants is to get a call saying something happened at school,” said parent Shavonta Grace.

The head of the school says the man entered the building, and placed the gun down, before running down a hallway and into a classroom.

“I’m just so thankful for the swift action of our staff to make sure that the gun did not leave the foyer of the school,” said Renew Academy CEO Tanya Bryant.

School staff and New Orleans police apprehended Harris without incident. No shots were fired and no injuries were reported.

Mental health counselors have been brought on site to support students and staff. Parents have been notified and are allowed to take their children home if they wish.

Harris was arrested and facing multiple charges, including having a gun on school property.

However, if that law didn't dissuade him from carrying a gun into a school, I'm pretty sure it won't stop people with far worse intentions.

We don't know what he was allegedly trying to do in the first place, but it doesn't sound like he had any intention of hurting anyone. If he did, he'd have started in that foyer and likely not stopped until someone stopped him or he ran out of ammunition.

The status of the school as a gun-free zone did nothing.

Now, parents are asking about other security measures, such as metal detectors and security guards. It sounds like they want their kids' school hardened because the laws aren't doing jack squat.

And I agree with them. 

If Harris had intended to kill as many people as possible in this school, metal detectors and an unarmed guard wouldn't have stopped him. A school resource officer might not have, either.

Of course, if the teachers themselves had been armed, it's entirely likely that when a would-be killer tried to rack up his kill count, he'd have found himself the recipient of 124 grains of attitude adjustment delivered at high velocity and never hurt another living soul again.